When you drop a button control on the ASP.Net Web Form, by default it will act as a Submit Button Control. The submit button performs Auto Postback of the Web Form to the web server. This means, when user clicks the button, the browser will send the Form’s data to the web server. Web Server will process the information and replies back to the web browser. This process is called Postback. In this Lab, we will create a web form with a button control and text field and see how button click works & performs Postback.